If you are a sprinter, how you load the forefoot bipod might be a variable for speed or injury. Tendons can change their cross sectional area, if you load them.

Screen Shot 2019-06-10 at 6.17.21 PM.png

Of course this article is not exclusive for sprinters, it pertains to any running sport, even endurance.

Maximum isometric force had increased by 49% and tendon CSA by 17% !
Tendons can change their cross sectional area, if you load them.

Here I show lateral forefoot loading in a heel raise, and a medial forefoot loading in heel raise. This has to be part of the discovery process outlined below. Forefoot types will play into the loading choice, and unequal strength of the medial or lateral calf compartment will also play into the loading choice made. Where do you need to put your strength ? And is the forefoot competent to take that loading challenge ? Meaning, do they have a forefoot valgus? A forefoot supinatus ? These things matter. If you are a sprinter, how you load the forefoot bipod might be a variable of foot type, asymmetrical posterior compartment strength, or foot strike pattern in the frontal plane (search our blog for cross over gait and glute medius targeting strategies for step width) ,or a combination of several or all of the above. These things matter, and why and where you put your strength matters, if you are even aware of where and how you are putting the loads, and why of course. Of course, then there are people like the recent Outside online article that says how you foot strike doesn’t matter, but it does matter. But of course, if you do not know the things we have just mentioned, it is easy to write such an article.

Isometrics are useful, they have their place. In a recent podcast we discussed the place and time to use isometrics, isotonics, eccentrics and concentrics.
One of the goals in a tendinopathy is to restore the tendon stiffness. Isometrics are a safe way to load the muscle tendon complex without engaging a movement that might have to go through a painful arc of movement. With isometrics here is neurologic overspill into the painful arc without having to actually go there.
The key seems to be load. More load seems to get most people further along. Remember, the tendon is often problematic because it is inflammed and cannot provide a stiffness across its expanse. Heavy isometric loading seems to be a huge key for most cases. But, we have to say it here, not everyone fits this mold. Some tendons, in some people, will respond better to eccentrics, and strangely enough, some cases like stretching (perhaps because this is a subset of an eccentric it seems or because there is a range of motion issue in the joint that is a subset of the problem). Now the literature suggests that stretching is foolish, but each case is unique all in its own way, and finding what works for a client is their medicine, regardless of what the literature and research says.
Finding the right load for a given tendon and a right frequency of loading and duraction of loading is also case by case specific. Part of finding the right loading position is a discovery process as well, as noted in the photos above. Finding the fascicles you want to load, and the ones you do not want to load (painful) can be a challenging discovery process for you and your client. Finding the right slice of the pie to load, and the ones not to load takes experimentation. When it is the achilles complex, finding the safe However, if one is looking for a rough template to build from, brief, often, heavy painfree loads is a good template recipe to start with.

Here, in this Geremia et al article, "ultrasound was used to determine Achilles tendon cross-sectional area (CSA), length and elongation as a function of plantar flexion torque during voluntary plantar flexion."
They discovered that, "At the end of the training program, maximum isometric force had increased by 49% and tendon CSA by 17%, but tendon length, maximal tendon elongation and maximal strain were unchanged. Hence, tendon stiffness had increased by 82%, and so had Young’s modulus, by 86%.

Effects of high loading by eccentric triceps surae training on Achilles tendon properties in humans. Jeam Marcel Geremia, Bruno Manfredini Baroni, Maarten Frank Bobbert, Rodrigo Rico Bini, Fabio Juner Lanferdini, Marco Aurélio Vaz
European Journal of Applied Physiology
August 2018, Volume 118, Issue 8, pp 1725–1736

Podcast 123: The Rear foot: Understanding your RearFoot type

Key tag words:
foot types, rearfoot, forefoot, pronation, supination, shoe fit, forefoot varus, forefoot supinatus, rearfoot inversion, ankle rocker, injuries, rehab, corrective exercises

Rearfoot varus and Rearfoot valgus. Knowing the anatomy of your rear foot and its anatomic and functional posturing can lead to many problems in anyone. If you do not know the rearfoot type and posturing, you will not understand the rest of the foot mechanics. Without this knowledge, you will not know the reason for midfoot or forefoot problems, not understand what shoe you are in, or even why the shoe, footbed, orthotic you have chosen is either not fixing your problems, or causing them.  Join us on a journey down the rearfoot rabbit hole over the next hour.  Plus a few funny stories to lighten the biomechanics-heavy dialogue.
 

Show links:
http://traffic.libsyn.com/thegaitguys/pod_123final_cut.mp3

http://thegaitguys.libsyn.com/podcast-123-the-rear-foot-understanding-your-rearfoot-type

Show sponsors:
www.newbalancechicago.com

www.thegaitguys.com
That is our website, and it is all you need to remember. Everything you want, need and wish for is right there on the site.
Interested in our stuff ? Want to buy some of our lectures or our National Shoe Fit program? Click here (thegaitguys.com or thegaitguys.tumblr.com) and you will come to our websites. In the tabs, you will find tabs for STORE, SEMINARS, BOOK etc. We also lecture every 3rd Wednesday of the month on onlineCE.com. We have an extensive catalogued library of our courses there, you can take them any time for a nominal fee (~$20).
 
Our podcast is on iTunes, Soundcloud, and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.
 
Show Notes:

https://www.ncbi.nlm.nih.gov/pubmed/27134364

https://www.ncbi.nlm.nih.gov/pubmed/25364132

RearFoot positions:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3588658/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3990938/

Powers CM, Maffucci R, Hampton S. Rearfoot posture in subjects with patellofemoral pain. J Orthop Sports Phys Ther. 1995 Oct;22(4):155-60.

Power V, Clifford AM. The Effects of Rearfoot Position on Lower Limb Kinematics during Bilateral Squatting in Asymptomatic Individuals with a Pronated Foot Type. J Hum Kinet. 2012 Mar;31:5-15. doi: 10.2478/v10078-012-0001-0. Epub 2012 Apr 3.

Shultz SP, Song J, Kraszewski AP, Hafer JF, Rao S, Backus , Mootanah R, Hillstrom HJ. An Investigation of Structure, Flexibility and Function Variables that Discriminate Asymptomatic Foot Types. J Appl Biomech. 2016 Dec 19:1-25. [Epub ahead of print]

 

Forefoot Varus or Forefoot Supinatus?   Forefoot varus is a fixed, frontal plane deformity where the forefoot is inverted with respect to the rearfoot. Forefoot varus is normal in early childhood, but should not persist past 6 years of age (i.e. when developmental valgus rotation of forefoot on rearfoot is complete, and plantar aspects of fore- and rearfoot become parallel to, and on same plane as, one another (1)  Forefoot supinatus is the supination of the forefoot that develops with adult acquired flatfoot deformity. This is an acquired soft tissue adaptation in which the forefoot is inverted on the rearfoot. Forefoot supinatus is a reducible deformity. Forefoot supinatus can mimic, and often be mistaken for, a forefoot varus. (2)  A forefoot varus differs from forefoot supinatus in that a forefoot varus is a congenital osseous where a forefoot supinatus is acquired and develops because of subtalar joint pronation.  “Interestingly, only internal rotation of the hip was increased in subjects with FV – no differences were present in hip adduction and knee abduction between subjects with and without FV. The authors nevertheless conclude that FV causes significant changes in mechanics of proximal segments in the lower extremity and speculate that during high-speed weight-bearing tasks such as running, the effects of FV on proximal segments in the kinetic chain might be more pronounced.”  We wonder if the folks in this study had a true forefoot varus, or actually a forefoot supinatus (3).     The Gait Guys   1. Illustrated Dictionary of Podiatry and Foot Science by Jean Mooney © 2009 Elsevier Limited.  2. Evans EL1, Catanzariti AR2. Forefoot supinatus.  Clin Podiatr Med Surg. 2014 Jul;31(3):405-13. doi: 10.1016/j.cpm.2014.03.009.  3. Scattone Silva R1, Maciel CD2, Serrão FV3. The effects of forefoot varus on hip and knee kinematics during single-leg squat. Man Ther. 2015 Feb;20(1):79-83. doi: 10.1016/j.math.2014.07.001. Epub 2014 Jul 12.

Forefoot Varus or Forefoot Supinatus?

Forefoot varus is a fixed, frontal plane deformity where the forefoot is inverted with respect to the rearfoot. Forefoot varus is normal in early childhood, but should not persist past 6 years of age (i.e. when developmental valgus rotation of forefoot on rearfoot is complete, and plantar aspects of fore- and rearfoot become parallel to, and on same plane as, one another (1)

Forefoot supinatus is the supination of the forefoot that develops with adult acquired flatfoot deformity. This is an acquired soft tissue adaptation in which the forefoot is inverted on the rearfoot. Forefoot supinatus is a reducible deformity. Forefoot supinatus can mimic, and often be mistaken for, a forefoot varus. (2)

A forefoot varus differs from forefoot supinatus in that a forefoot varus is a congenital osseous where a forefoot supinatus is acquired and develops because of subtalar joint pronation.

“Interestingly, only internal rotation of the hip was increased in subjects with FV – no differences were present in hip adduction and knee abduction between subjects with and without FV. The authors nevertheless conclude that FV causes significant changes in mechanics of proximal segments in the lower extremity and speculate that during high-speed weight-bearing tasks such as running, the effects of FV on proximal segments in the kinetic chain might be more pronounced.”

We wonder if the folks in this study had a true forefoot varus, or actually a forefoot supinatus (3).


The Gait Guys


1. Illustrated Dictionary of Podiatry and Foot Science by Jean Mooney © 2009 Elsevier Limited.

2. Evans EL1, Catanzariti AR2. Forefoot supinatus.
Clin Podiatr Med Surg. 2014 Jul;31(3):405-13. doi: 10.1016/j.cpm.2014.03.009.

3. Scattone Silva R1, Maciel CD2, Serrão FV3. The effects of forefoot varus on hip and knee kinematics during single-leg squat. Man Ther. 2015 Feb;20(1):79-83. doi: 10.1016/j.math.2014.07.001. Epub 2014 Jul 12.